Fewer than one in four of the government's hundreds of national infrastructure projects – including road, rail and energy schemes – will be completed during this parliament, research by the Guardian has found.

The figures will feed growing pressure on the chancellor, George Osborne, before budget to speed up capital spending on homes, transport and utilities.

Although the Treasury says that spending on national infrastructure rose by £4bn a year under the previous Labour government, to £33bn in the first two years of this parliament, much of that will have been driven by existing commitments made during the previous administration.

About £3bn a year of the increase is accounted for by just two major projects, the Olympics and Crossrail, a major London rail project which began in 2009 and will not open until 2018.

Officials admit, however, there is no guarantee that total spending will continue at that level. Labour calculates public spending will fall over the rest of this parliament.

Meanwhile, private investment is expected to fill the gap. Private investment in infrastructure projects is expected to rise from nearly two-thirds of total expenditure in 2011, as estimated by the National Audit Office, to approximately three-quarters of future schemes.

That private investment is far from secure however: just £1bn of £21bn of private investment announced by the government in the autumn of 2011 has been raised so far. The amount raised so far is still "soft money" while pension funds wait for more details of the government's plans, including costly guarantees that they will not have to take a hit if a project suffers serious delivery or budget problems.

Worryingly for ministers, construction output has fallen about 10% since the general election, including notable drops in housebuilding and repairs, while spending on other infrastructure of national importance has flatlined.

As an example of the apparent paralysis, Highways Agency figures provided to the Guardian show just three major road projects have begun construction since the coalition government was formed, alongside another four schemes to improve motorway management.

Ministers have promised a further 17 will begin by 2015, but no dates for starting construction have been given. Total road spending committed by the coalition from 2011 to 2015 is £3.3bn, almost exactly the same as spent by the last government in the previous four years.

Meanwhile, two major national policy statements that should guide decisions on spending – on road and rail networks, and on aviation – are both overdue, while official figures last summer showed that the number of planning applications decided within the government target of 13 weeks had fallen in the previous year.

Perhaps the greatest frustration among critics, however, is the government's struggle to clarify what money is available in the short term.

The sweeping national infrastructure plan is updated every year, including dozens if not hundreds of schemes that will not start buying equipment and materials or employing labour until long after the next general election.

Even the clearest information, the regularly updated "pipeline" of more than 500 infrastructure projects published by the Treasury, is often scant on detail: hundreds of energy, flooding, waste, road and rail investments are lacking a start date, while dozens of others are given a clearly erroneous start or finish date of 1905.

With so few start dates, analysts are forced to rely on a fuller list of expected completion dates: of the 577 projects, 129 are due to start operating in or before 2015. The pipeline list includes 12 new nuclear reactors, starting with two at Hinkley in Somerset due to open in 2017, £11.5bn for a new deep underground nuclear waste store not expected before 2040, upgrades to major London airports and a new terminal at Manchester airport, and improvements to the M1, M3, M4, M5, M6, and M25.